Rocket Science for Earthlings
a continuing series for the gravitationally
impaired.
But can a human body actually survive direct exposure to space? Actually, Yes. I have seen only one report of the effects, which I suspect came out of Nazi Germany and therefore was gained at the loss of human life, but it does provide a better description than some movies I've seen. Human skin makes a pretty good spacesuit. On exposure to vacuum, all the openings in the body expel fluids, you salivate, urinate, defecate, tear, and lactate. It gets pretty messy. Your bowel distends because of the gas in your gut. However, until you loose consciousness due to a lack of oxygen, that's pretty much it, no, your blood doesn't immediately boil. The "HAL open the pod bay door" scene in the movie 2001 is actually a good portrayal of someone being exposed to vacuum. You can expose your hands to vacuum for up to twenty minutes with no permanent effects.
Gravity is the next thing on the agenda. The old idea of spinning the space station to produce gravity is still a good one. One of the Gemini flights did a small experiment with artificial gravity when the spacecraft was tethered to an Agena docking vehicle. Only a small amount of acceleration was produced but it demonstrated that it could be done. Experiments on Earth seem to indicate that 1/4 RPM is about the maximum rotation rate that can be used without making people dizzy. Since Gemini no experiments have been done in space to verify that conclusion.
The most dangerous thing about living in space is the thing you can't see, radiation. On Earth the atmosphere shields us from the high radiation levels of space. If you pile up a square inch column of dirt about 11 feet high, you will get 14.7 pounds. This is exactly the same amount of shielding you get from Earth's atmosphere, so wherever you plan on spending a lot of time in Space, be sure that about 11 feet of dirt is between you and the great void beyond, a little more wouldn't hurt. Of course you don't have to have the radiation shield right next to you, or even inside the pressure hull with you, it can be parked in zero gravity outside somewhere.
So, you have a pressure hull, with air inside, spinning to produce gravity, with a lot of dirt sitting outside to block the radiation, add cable TV and your all set for life in the future. But can you do any of the things you need to do in space? That's where robots, artificial intelligence, and virtual reality come in. NASA is and should be working on methods by which humans can stay in their protected little habitats, yet by electronic means reach outside to do the things that need to be done. It would seem that Space was really made for our electronic offspring.